(function() {
    'use strict';
    // the 0.0001 offset fixes a bug in Chrome 27
    var PIx2 = (Math.PI * 2) - 0.0001;
    /**
     * Ring constructor
     * @constructor
     * @augments Konva.Shape
     * @param {Object} config
     * @param {Number} config.innerRadius
     * @param {Number} config.outerRadius
     * @param {Boolean} [config.clockwise]
     * @@shapeParams
     * @@nodeParams
     * @example
     * var ring = new Konva.Ring({
     *   innerRadius: 40,
     *   outerRadius: 80,
     *   fill: 'red',
     *   stroke: 'black',
     *   strokeWidth: 5
     * });
     */
    Konva.Ring = function(config) {
        this.___init(config);
    };

    Konva.Ring.prototype = {
        _centroid: true,
        ___init: function(config) {
            // call super constructor
            Konva.Shape.call(this, config);
            this.className = 'Ring';
            this.sceneFunc(this._sceneFunc);
        },
        _sceneFunc: function(context) {
            context.beginPath();
            context.arc(0, 0, this.getInnerRadius(), 0, PIx2, false);
            context.moveTo(this.getOuterRadius(), 0);
            context.arc(0, 0, this.getOuterRadius(), PIx2, 0, true);
            context.closePath();
            context.fillStrokeShape(this);
        },
        // implements Shape.prototype.getWidth()
        getWidth: function() {
            return this.getOuterRadius() * 2;
        },
        // implements Shape.prototype.getHeight()
        getHeight: function() {
            return this.getOuterRadius() * 2;
        },
        // implements Shape.prototype.setWidth()
        setWidth: function(width) {
            Konva.Node.prototype.setWidth.call(this, width);
            if (this.outerRadius() !== width / 2) {
                this.setOuterRadius(width / 2);
            }
        },
        // implements Shape.prototype.setHeight()
        setHeight: function(height) {
            Konva.Node.prototype.setHeight.call(this, height);
            if (this.outerRadius() !== height / 2) {
                this.setOuterRadius(height / 2);
            }
        },
        setOuterRadius: function(val) {
            this._setAttr('outerRadius', val);
            this.setWidth(val * 2);
            this.setHeight(val * 2);
        }
    };
    Konva.Util.extend(Konva.Ring, Konva.Shape);

    // add getters setters
    Konva.Factory.addGetterSetter(Konva.Ring, 'innerRadius', 0);

    /**
     * get/set innerRadius
     * @name innerRadius
     * @method
     * @memberof Konva.Ring.prototype
     * @param {Number} innerRadius
     * @returns {Number}
     * @example
     * // get inner radius
     * var innerRadius = ring.innerRadius();
     *
     * // set inner radius
     * ring.innerRadius(20);
     */
    Konva.Factory.addGetter(Konva.Ring, 'outerRadius', 0);
    Konva.Factory.addOverloadedGetterSetter(Konva.Ring, 'outerRadius');

    /**
     * get/set outerRadius
     * @name outerRadius
     * @method
     * @memberof Konva.Ring.prototype
     * @param {Number} outerRadius
     * @returns {Number}
     * @example
     * // get outer radius
     * var outerRadius = ring.outerRadius();
     *
     * // set outer radius
     * ring.outerRadius(20);
     */

    Konva.Collection.mapMethods(Konva.Ring);
})();